Paracoccus denitrificans offers a dual-function biotechnological platform for sustainable waste management and biopolymer production. This metabolically versatile bacterium not only contributes to nitrogen removal in wastewater through denitrification, but also accumulates valuable compounds such as polyhydroxyalkanoates (PHAs) including Poly(3-hydroxybutyrate) [P(3HB)], Poly(3-hydroxyvalerate) [P(3HV)], and their copolymer Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) under nutrient-limiting conditions.  These biopolymers present biodegradable and biocompatible alternatives to petrochemical plastics, aligning with circular economy principles and Net Zero strategies by reducing carbon emissions, fossil resource dependence, are home compostable and degradable in the soil and marine environment. These do not produce microplastics. Thus PHAs play an important role in today’s circular economy and sustainability. Utilising industrial effluents and agricultural by-products as feedstocks, P. denitrificans can integrate into existing water treatment infrastructures, enabling concurrent denitrification and bioplastic synthesis. P. dentrificans is one of very few organisms that can synthesise P(3HV) as a homopolymer. Currently, the most used and produced biopolyester of bacterial origin is P(3HB), utilised across various fields such as packaging and biomedical applications. While, P(3HB) is a good option for certain applications, there are applications that could be better suited using P(3HV) which offers less crystallinity, better flexibility, and processability when compared with P(3HB). In our lab we were able to synthesise a whole range of polymers such as P(3HB), P(3HV), and PHBV using P. denitrificans as a synthesis platform using fatty acids and alcohols as a feedstock. Ongoing work focuses on optimising P(3HV) production.